Gunmen killed eight people in north Nigeria and a mob torched an Islamic school in the south, as a fuel strike and growing religious tension rattled Africa's oil-rich giant.

Amid the sectarian and social turmoil, Nobel literature prize laureate Wole Soyinka, one of the country's most respected voices, warned that the continent's most populous nation was heading toward civil war.

View Unrest in Nigeria in a larger map A two-day old general strike has paralysed the country and sent President Goodluck Jonathan's government -- already battling a spate of bloody attacks by the Islamist sect Boko Haram -- into crisis mode.

Analysts said the tension in the country that is Africa's top oil producer contributed to rising world oil prices, with the barrel of Brent North Sea crude gaining 82 cents to $113.27 in early afternoon trade.

In the latest attack blamed on Boko Haram, gunmen killed eight people, including five police officers, in a pub in Potiskum town in the northern state of Yobe before speeding off on a motorcycle.

A doctor said eight bodies were brought to the local morgue, including "five policemen, a bartender, a customer and a 10-year-old girl".

Police confirmed the shooting but did not give a casualty toll.

In the country's south, a mob burnt part of the central mosque complex in the city of Benin, where earlier clashes killed five, bringing to 11 the number of people killed in incidents related to the strike over two days.

Witnesses said an Islamic school adjacent to the mosque was torched and a bus parked next to it also went up in flames.

The unrest in the city started Monday amid protests against the government's January 1 scrapping of fuel subsidies, which caused petrol prices to more than double, sparking widespread anger.

Most of Nigeria's 160 million people live on less than $2 a day.

During the rally in Benin, a crowd split off to attack a mosque and terrorise people in neighbourhoods that are mainly Hausa, an ethnic group that dominates the north and is overwhelmingly Muslim.

Nigeria is roughly divided between a predominantly Christian south and mainly Muslim north.

Recent violence targetting Christians -- including a series of Christmas Day bombings -- has sparked warnings from Christian leaders that they will defend themselves and stoked fears of a wider religious conflict.

Soyinka, who became Africa's first Nobel prize for literature winner in 1986, warned in a BBC interview that the country could face a new conflict akin to its 1960s war, which killed more than a million people.

"It's not an unrealistic comparison -- it's certainly based on many similarities... We see the nation heading towards a civil war," he said.

Jonathan on Sunday warned that the violence blamed on Boko Haram was worse than the 1967-70 civil war, saying also that there were sect sympathisers in the government and within the security agencies.

The president on Tuesday met his security chiefs in the capital Abuja as he faced the toughest challenge since taking the post in 2010, battling on two fronts -- against the social protests and Boko Haram.

Gangs set up roadblocks of burning tyres on major roads in the economic capital Lagos and threw stones at cars while extorting cash from drivers.

Protesters marched through the streets to the sound of blaring afrobeat music, sometimes with soldiers clapping and taking pictures.

One person brought a goat wrapped in a union flag while others carried a mock coffin labelled "Badluck", a play on the president's name.

A 24-hour curfew was imposed in the northern city of Kaduna for fear protests would degenerate after thousands of fuel protesters tried for two successive days to force their way into a government complex.

Residents said police fired teargas to disperse thousands of young men who besieged the complex for a second day running.

Reuben Buhari, a spokesman for Kaduna state -- where last year hundreds were killed in three days of post-election violence -- said the protest was "hijacked by miscreants who started attacking people and breaking cars".

The government says it scrapped the fuel subsidies because they cost more than $8 billion (6.3 billion euros) in 2011 and that it needs the money to improve the country's woefully inadequate infrastructure.

Nigerians have viewed the fuel subsidies as their only benefit from the nation's vast oil wealth, and many people lack any real trust in the government after years of deeply rooted corruption.